# CVE-2024-21499: Improper Neutralization of HTTP Headers in github.com/greenpau/caddy-security

> Attackers can bypass security mechanisms or cause TLS confusion by injecting the X-Forwarded-Proto header in Caddy security plugin.

- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 17 Feb 2024
- **Updated:** 1 Aug 2024
- **Also known as:** GHSA-r969-783f-6jqr, GO-2024-2562

## What is CVE-2024-21499?

CVE-2024-21499 is a medium-severity vulnerability in github.com/greenpau/caddy-security, published on 17 Feb 2024. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

All versions of the package github.com/greenpau/caddy-security are vulnerable to HTTP Header Injection via the X-Forwarded-Proto header due to redirecting to the injected protocol.Exploiting this vulnerability could lead to bypass of security mechanisms or confusion in handling TLS.

Weakness: CWE-116 (Improper Encoding or Escaping of Output), CWE-644 (Improper Neutralization of HTTP Headers for Scripting Syntax)

## Which versions are affected by CVE-2024-21499?

3 open source packages ship an affected version, including github.com/greenpau/caddy-security. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/greenpau/caddy-security` | Go | All versions | None |
| `github.com/greenpau/caddy-security` | Go | All versions to 1.1.23 | None |
| `github.com/greenpau/caddy-security` | Go | All versions to 1.1.23 | None |

Products: Greenpau Caddy-Security.

## How do I fix CVE-2024-21499?

No fix has been published for CVE-2024-21499 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-21499 being exploited?

There is no known exploitation of CVE-2024-21499 in the wild and no public exploit code.

## Other vulnerabilities in github.com/greenpau/caddy-security

- [CVE-2024-21495](https://insights.sbomify.com/CVE-2024-21495/): Use of Insufficiently Random Values in github.com/greenpau/caddy-security (medium 6.5)
- [CVE-2024-21494](https://insights.sbomify.com/CVE-2024-21494/): Authentication Bypass by Spoofing in github.com/greenpau/caddy-security (medium 5.4)
- [CVE-2024-21497](https://insights.sbomify.com/CVE-2024-21497/): Open Redirect in github.com/greenpau/caddy-security (medium 5.4)
- [CVE-2024-21493](https://insights.sbomify.com/CVE-2024-21493/): Improper Validation of Array Index in github.com/greenpau/caddy-security (medium 5.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-21499 and fix it if it is affected.

What it is: CVE-2024-21499 is a medium-severity vulnerability in github.com/greenpau/caddy-security, published on 17 Feb 2024. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2024-21499 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/greenpau/caddy-security (Go): affected all versions; no fix listed
- github.com/greenpau/caddy-security (Go): affected all versions up to 1.1.23; no fix listed
- github.com/greenpau/caddy-security (Go): affected all versions up to 1.1.23; no fix listed

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2024-21499/ (Markdown: https://insights.sbomify.com/CVE-2024-21499/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-21499
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-21499
- OSV: https://osv.dev/vulnerability/CVE-2024-21499

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-21499/
Summaries are generated and may contain mistakes; the official description above is the record.